Washing machine on a smart plug seems to be a good compromise, as it allows you to:
a) Make it come on when the electricity is cheap
b) Measure how many electrons it uses
c) Generate notifications when it finishes
(ie. the sum total of 'smart' things you might reasonably want to do with a washing machine) without the machine itself getting Ideas above its station, risk becoming part of a Chinese botnet or being bricked remotely by the manufacturer.
I've never actually looked at how smart appliances work, but I'm assuming there's some godawful blingly bongly app that over-complicates the process of selecting "40° synthetics wash. Again." while trying to sell you overpriced consumables, extended warranties or (assuming Amazon don't hold the patent on this sort of thing) another washing machine.